Two differenct sources of errors may occur in the implementation of the PE methods; a phase error introduced in the approximation of a pseudo-differential operator and an amplitude error generated from the starting field. First, the inherent phase errors introduced in the solution are analyzed for a case where the normal mode solution to the wave equation is valid, when the sound is propagated in a downward refracting atmosphere. The angular limitations for the different parabolic approximations are deduced, and calculations showing shifts in the starter as the second source of error is investigated. Numerical and analytical starters are compared for source locations close to the ground. The spectral properties of several starters are presented.
|Title of host publication||Seventh International Symposium on Long Range Sound Propagation|
|Place of Publication||Ecully|
|Publisher||Laboratoire de Mécanique des Fluides et d'Acoustique, Ecole Centrale de Lyon|
|Publication status||Published - 1996|
|Event||7th International Symposium on Long Range Sound Propagation - Lyon, France|
Duration: 24 Jul 1996 → 26 Jul 1996
Conference number: 7
|Conference||7th International Symposium on Long Range Sound Propagation|
|Period||24/07/1996 → 26/07/1996|
Arranz, M. G. (1996). Approximations in the PE-method: Phase and level errors in a downward refracting atmosphere. In Seventh International Symposium on Long Range Sound Propagation (pp. 235-255). Laboratoire de Mécanique des Fluides et d'Acoustique, Ecole Centrale de Lyon.